[libcamera-devel] [PATCH v4 17/21] libcamera: simple: Fill stride and frameSize at config validation

[Paul Elder]

Fill the stride and frameSize fields of the StreamConfiguration at
configuration validation time instead of at camera configuration time.
This allows applications to get the stride when trying a configuration
without modifying the active configuration of the camera.

Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>

---
Changes in v4:
- fix converter's stride and frameSize (get it via tryFormat instead of
  calculation)
- merge converter's stride and frameSize to one function
- return error if tryFormat fails
- mention motivation in commit message

New in v3
---
 src/libcamera/pipeline/simple/converter.cpp | 19 +++++++++++++++
 src/libcamera/pipeline/simple/converter.h   |  4 +++
 src/libcamera/pipeline/simple/simple.cpp    | 27 +++++++++++++++++++--
 3 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/src/libcamera/pipeline/simple/converter.cpp b/src/libcamera/pipeline/simple/converter.cpp
index e5e2f0f..cef1503 100644
--- a/src/libcamera/pipeline/simple/converter.cpp
+++ b/src/libcamera/pipeline/simple/converter.cpp
@@ -261,4 +261,23 @@ void SimpleConverter::outputBufferReady(FrameBuffer *buffer)
 	}
 }
 
+int SimpleConverter::strideAndFrameSize(const Size &size,
+					const PixelFormat &pixelFormat,
+					unsigned int *strideOut,
+					unsigned int *frameSizeOut)
+{
+	V4L2DeviceFormat format = {};
+	format.fourcc = m2m_->capture()->toV4L2PixelFormat(pixelFormat);
+	format.size = size;
+
+	int ret = m2m_->capture()->tryFormat(&format);
+	if (ret < 0)
+		return -1;
+
+	*strideOut = format.planes[0].bpl;
+	*frameSizeOut = format.planes[0].size;
+
+	return 0;
+}
+
 } /* namespace libcamera */
diff --git a/src/libcamera/pipeline/simple/converter.h b/src/libcamera/pipeline/simple/converter.h
index ef18cf7..3e46988 100644
--- a/src/libcamera/pipeline/simple/converter.h
+++ b/src/libcamera/pipeline/simple/converter.h
@@ -46,6 +46,10 @@ public:
 
 	int queueBuffers(FrameBuffer *input, FrameBuffer *output);
 
+	int strideAndFrameSize(const Size &size, const PixelFormat &pixelFormat,
+			       unsigned int *strideOut,
+			       unsigned int *frameSizeOut);
+
 	Signal<FrameBuffer *, FrameBuffer *> bufferReady;
 
 private:
diff --git a/src/libcamera/pipeline/simple/simple.cpp b/src/libcamera/pipeline/simple/simple.cpp
index 1ec8d0f..0c52b47 100644
--- a/src/libcamera/pipeline/simple/simple.cpp
+++ b/src/libcamera/pipeline/simple/simple.cpp
@@ -457,6 +457,31 @@ CameraConfiguration::Status SimpleCameraConfiguration::validate()
 
 	cfg.bufferCount = 3;
 
+
+	/* Set the stride and frameSize. */
+	if (!needConversion_) {
+		V4L2DeviceFormat format = {};
+		format.fourcc = data_->video_->toV4L2PixelFormat(cfg.pixelFormat);
+		format.size = cfg.size;
+
+		int ret = data_->video_->tryFormat(&format);
+		if (ret < 0)
+			return Invalid;
+
+		cfg.stride = format.planes[0].bpl;
+		cfg.frameSize = format.planes[0].size;
+
+		return status;
+	}
+
+	SimplePipelineHandler *pipe = static_cast<SimplePipelineHandler *>(data_->pipe_);
+	SimpleConverter *converter = pipe->converter();
+
+	int ret = converter->strideAndFrameSize(cfg.size, cfg.pixelFormat,
+						&cfg.stride, &cfg.frameSize);
+	if (ret < 0)
+		return Invalid;
+
 	return status;
 }
 
@@ -557,8 +582,6 @@ int SimplePipelineHandler::configure(Camera *camera, CameraConfiguration *c)
 		return -EINVAL;
 	}
 
-	cfg.stride = captureFormat.planes[0].bpl;
-
 	/* Configure the converter if required. */
 	useConverter_ = config->needConversion();
 
-- 
2.27.0